To optimize the formulation of the doxorubicinmagnetic thermosensitive liposomes (DOX-MTSLs) was optimized by orthogonal design and evaluated its property.
The optimum recipe of DOX-MTSLs was founded as DOX/DPPC of 120(m/m), DPPC/Chol of 41 (mol/mol), the concentration of magnetic fluid 15 mg · mL-1, pH value of 7.4. The average entrapment efficiency of three batches of DOX-MTSLs(100416,100507,100517 self-preparation) were(82.77 ±0.88) %, (83.03 ±1.38)% and (80.68 ±0.42)% (n=3). The average particle size of doxorubicinmagnetic thermosensitive liposomes were 177.1 nm, and the polydispersity index(PDI) was 0.700. When the temperature increased from (25 ± 0.5)°C to (37 ± 0.5)°C, the in vitrodrug release was very slow and incomplete (15.45% and 19.54%) even up to 10 h. However, at the phase transitiontemperature(Tm) 41°C, the in vitrodrug release significantly reached 90.99% within 2 h and continued to release. The DOX-MTSLs was showed to be temperature dependent and the in vitro release model was fitting the kinetic equation of Higuchi at(41±0.5)°C. The heatingtemperature and balanceable temperature of DOX-MTSLs(Fe3O2 3.19 mg · mL-1) were respectively raised to 39.9°C in 10 min and to 56.7°C in 40 min in high frequency induction heatingequipment of oscillation frequency 80 kHz and current 12A.
CONCLUSION:
The optimized conditions can be obtained with high entrapment efficiency, good thermosensitivity and perfect magnetic susceptibility to reach the expectation.